Rotating machinery, such as gas turbine engines, centrifugal compressors, steam turbines, etc., typically requires washing on a periodic basis. Washing is usually performed to remove dirt, dust, and other contaminates that collect along the flow path of the machine. Washes are usually conducted by injecting water or a liquid cleaning agent into the inlet airstream of the machine, so that the water or cleaning agent is ingested by the machine upon reaching the inlet thereof. Alternatively, the water or cleaning agent can be injected directly into the flow path within the machine.
Washes may be performed on an on-line basis, i.e., while the machine is operating. Alternatively, washes can be performed on an off-line basis, i.e., while the rotating components of the machine are spun at relatively low speed using the machine's starter or other suitable means; this type of wash is commonly referred to as a “crank wash.”
Moreover, water or other types of heat-transfer media can be introduced into the inlet airstream of the machine, to increase the density of the inlet air and thereby augment the power of the machine.
The water or other fluid is usually introduced using a series of spray nozzles mounted upstream of the machine, on the bellmouth, inlet scroll, or other inlet structure. Spray nozzles can also be mounted on one or more casings of the machine itself, so that the spray nozzles extend into the flow path within the machine.
The spray nozzles and their associated mounting hardware are usually secured in place using welds, or other permanent or semi-permanent attachment means, to minimize the potential for the spray nozzles and mounting hardware to become detached. Detachment of a spray nozzle or its mounting hardware can result in catastrophic damage to the machine as the spray nozzle or mounting hardware travel downstream through the machine.
Mounting the spray nozzles and their associated mounting hardware using welds, or other permanent or semi-permanent connecting means, can make it difficult to remove and replace/reinstall the spray nozzles. Removal and replacement/reinstallation may be necessary when a nozzle requires cleaning or preventive maintenance, or when a different type of nozzle is required for a particular task.
For example, the disparate fluid pressures and flow rates associated with on-line and off-line washes usually necessitate the use of different spray nozzles for on-line and off-line washes. Switching between on-line and off-line nozzles can necessitate the time-consuming and labor-intensive process of breaking and subsequently re-forming welded connections. Alternatively, an installation may be configured to accommodate two separate sets of spray nozzles at the same time. The addition of a second set of spray nozzles requires additional space within the installation. The additional set of spray nozzles also requires an additional manifold or other means for delivering fluid to the additional spray nozzles, and additional mounting hardware.